新型聚合物纳米造影剂的合成及体内磁共振成像研究

文章采用可逆加成-断裂链转移聚合（reversible addition-fragmentation chain transfer polymerization，RAFT）方法，聚合得到以疏水性共聚物链段作为内核，亲水性共聚物链段作为支链的两亲性聚合物纳米颗粒，与氯化钆（Ⅲ）六水合物进行螯合反应后合成了一种新型的支化结构聚合物磁共振成像（magnetic resonance imaging，MRI）纳米造影剂P（DO3A-Gd $ ^{3+} $）。安全性试验结果表明，P（DO3A-Gd $ ^{3+} $）具有良好的生物安全性。体外MRI测试结果表明：P（DO3A-Gd $ ^{3+} $）的弛豫率为5.30（mmol/L） $ ^{-1} $·s $ ^{-1} $，高于临床造影剂Magnevist（2.94（mmol/L） $ ^{-1} $·s $ ^{-1} $）；P（DO3A-Gd $ ^{3+} $）具有显著的MRI造影增强效果。研究结果表明P（DO3A-Gd $ ^{3+} $）是一种优异的MRI造影剂，具有临床转化的潜力。

In this paper, a reversible addition-fragmentation chain transfer polymerization (RAFT) method was used to polymerize amphiphilic polymer nanoparticles with hydrophobic copolymer segments as the core and hydrophilic copolymer segments as the branched chains. A new branched structure polymer magnetic resonance imaging (MRI) nano-contrast agent P(DO3A-Gd $ ^{3+} $) was synthesized after chelating reaction of GdCl $ _{3} $·6H $ _{2} $O. The safety test results show that P(DO3A-Gd $ ^{3+} $) has good biosafety. In vitro MRI test results show that the relaxation rate of P(DO3A-Gd $ ^{3+} $) is 5.30 (mmol/L) $ ^{-1} $·s $ ^{-1} $, which is higher than that of the clinical contrast agent Magnevist(2.94 (mmol/L) $ ^{-1} $·s $ ^{-1} $). In vitro MRI test results show that P(DO3A-Gd $ ^{3+} $) has a significant MRI contrast enhancement effect. The results show that P(DO3A-Gd $ ^{3+} $) is an excellent MRI contrast agent and has the potential for clinical transformation.